Wood-burning boilers for home heating are still popular, despite the variety of models of gas and electric boilers, and there is a simple explanation for this: firewood is the most affordable type of fuel for country houses not connected to main gas.
The efficiency of modern wood-burning boilers is quite high, their efficiency reaches 85%, and not only wood, but also pellets, as well as wood waste, can be used as fuel.
Wood boilers used for heating country house, easy to connect and use - they are even easier to handle than a stove. If the installation and operation instructions are followed, they are safe. The only serious disadvantage of wood boilers is low level automation of the process: loading fuel into the boiler must be done manually. A way out of the situation could be a boiler with a function long burning or a combination boiler that runs on solid fuel and has an additional diesel or gas burner or electric heating element.
Despite the huge selection of models of wood-burning boilers, their design does not differ that much. Any wood-burning boiler for heating a house must have a fuel combustion chamber, a water heat exchanger, a chimney and an ash pan. The simplest wood-burning boiler resembles a potbelly stove with a water jacket: when wood burns in the firebox, the water heats up and enters the heating system. The efficiency of such a boiler is low, and the consumption of firewood is significant; due to incomplete combustion of fuel, part of the money literally goes down the drain. The design of modern boilers with a long-burning function is, of course, more complicated; the structure of such a boiler and its main elements are shown in the figure.
Firewood is loaded into the boiler through the top loading door in large quantities at once. The initial combustion of the fuel occurs in the gasification chamber. The supply of air, and with it the oxygen necessary for combustion, into this chamber is limited - this is how the intensity of combustion is regulated. In this mode, the wood does not burn, but smolders, producing more heat, and the water in the heat exchanger is heated. But the combustion process does not end there: during smoldering, smoke containing flammable gases is formed. These gases enter the second chamber - the combustion chamber, which also serves as an ash pit. The air supply to this chamber is no longer limited, and with a sufficient amount of oxygen, afterburning of gases occurs. The combustion temperature of the gas-air mixture is very high, and the heating efficiency of the water heat exchanger in this chamber is also very high. As a result, the smoke is cleared of ash and harmful combustible gases, which makes the new generation of wood-burning boilers very environmentally friendly.
Pyrolysis is a long-term combustion process
Video - the principle of operation of a long-burning wood-burning boiler
Smoke is removed through a chimney duct connected to the chimney and pipe. For cold supply and outlet hot water From the heat exchanger, the boiler is equipped with pipes. They are connected to the heating system according to the selected scheme. New generation boilers are equipped with automatic equipment that makes boiler maintenance as simple as possible:
- a temperature sensor that sends a signal to the primary air supply fan;
- a pressure sensor that signals when the normal value is exceeded;
- water pressure sensors in the system.
The efficiency of solid fuel boilers directly depends on the type and quality of fuel. If the boiler is designed to operate on wood, you must not load coal or peat briquettes into it! This will reduce the efficiency of the boiler and may damage it. It is also not recommended to use poorly dried firewood and coniferous wood to fire a wood-burning boiler - they burn with the formation of large amounts of steam, resins and soot, and the boiler will have to be cleaned much more often.
Wood boilers - choice
When choosing a wood-burning boiler, you must begin by calculating the required power - this parameter is indicated in the boiler’s passport and is measured in kilowatts. One kilowatt of boiler power is enough to heat ten square meters well-insulated room. For example, in conditions middle zone To heat a house with an area of 100 square meters, a boiler with a power of 10 kW is required. For frosty days and poorly insulated rooms, a power reserve of 20-30% is required. When choosing, you should pay attention not only to rated power, but also for the entire range in which the boiler can operate - in the fall and spring it is not advisable to fire the boiler at full capacity. If you plan to use the boiler also to produce hot water, then you will need an external boiler and an additional supply of boiler power based on the number of people permanently living in the house.
The boiler material – steel or cast iron – plays an important role. Steel boilers are lighter and have a simpler firebox design, which is easier to clean - just remove the ash from the ash pan. The smoke channel of steel boilers is longer, so heating of the coolant occurs more efficiently. Cast iron boilers have a shorter smoke channel, and a larger heat exchange area is achieved due to the ribbed surface in which combustion products settle; a cast iron boiler will have to be cleaned using brushes, scrapers and pokers. At the same time, the heat capacity of the boiler itself is higher for cast iron models.
A separate type is electric wood-burning boilers, which use electricity to further increase efficiency. Modern automation monitors the combustion process and influences it using valves that regulate the flow of incoming air into the firebox, so you can control the temperature in the firebox at a given level!
Wirbel steel wood burning boiler
An important indicator is the ratio of the volume of the loading chamber to the boiler power. To put it simply, how many times a day will you have to approach the boiler to load fuel. For steel boilers this figure is usually higher - on average 1.5-2.5 l/kW versus 1.1-1.4 l/kW for cast iron boilers - therefore, loading is carried out less frequently.
Be sure to make sure that there is an emergency cooling system and clarify the principle of its operation. This system may be needed if the boiler overheats and water boils in the heat exchanger. Boilers with a separate emergency cooling circuit are safer, but if emergency cooling is arranged by abruptly draining water from the heat exchanger and replacing it with cold water, make sure that the boiler is resistant to thermal shock.
Protection against burns is an important indicator, especially if access to the boiler room is open to strangers or children. A useful option is heat-insulated firebox handles, protective casings and grates, and thermal insulation of the hottest surfaces of the boiler.
Thermal protection of boilers is a mandatory safety condition
Wood boilers - installation requirements
Efficient and safe operation of a wood-burning boiler is impossible without correct installation. How to install a boiler with your own hands without violating safety rules?
Installation location
Any wood-burning boiler consumes a fairly large amount of air during operation, therefore, for low-power boilers that can be installed in common areas of the house, supply and exhaust ventilation is performed, and with a boiler power of more than 50 kW, it is necessary to install a separate boiler room with a useful room volume of 8 cubic meters. Wood-burning boilers are installed on a solid, level base with a fireproof coating - concrete, tile, porcelain stoneware. The walls must also be lined with non-combustible materials. The boiler room is equipped with forced ventilation.
Chimney requirements
The chimney for a wood-burning boiler is made of stainless steel, ceramics or thick-walled metal pipe. Optimal choice chimneys are made of stainless steel sandwich type. They are easily assembled from various elements - pipes held together with clamps, roof passages, unloading platforms. When bending such a chimney, bends are used at a certain angle. It is allowed to exhaust the boiler chimney not through the roof, but through the wall of the building. The height of the straight part of the chimney for stable draft in the boiler must be at least 6 meters for a 16 kW boiler and at least 10 meters for a 32 kW boiler, with a pipe diameter of 200 mm.
Service and maintenance
It is also necessary to clarify the service and warranty conditions for the selected boiler model, the proximity of service centers and the possibility of calling specialists for installation and repair. It may happen that servicing a cheaper model will cost significantly more than analogues from well-known companies with service centers in large cities.
Video - self-installation of solid fuel boilers
Wood-burning boilers for heating a house after installation are connected to a water heating system. For uninterrupted operation of the system, you can additionally install a tank-heater on electric heating elements, in this case you will not have to add firewood during your night's rest or when you are away from home.
For heating suburban buildings they use solid fuel boilers, if other types of fuel are unavailable or unreasonably expensive. For each heating season, the cottage owner has to prepare the necessary supply of firewood and coal, the volume of which depends on the area of the property and the quality of its thermal insulation, as well as the severity of the climatic conditions in the region of residence.
Most models of solid fuel boilers can provide a comfortable temperature in the house if they are heated twice a day at a strictly defined time. If you shift the time of ignition of fuel in the combustion chamber of the unit, then it becomes cold in the living room. The exception is long-burning boilers, which can maintain the required temperature in the house for several days. You can achieve the same result from a conventional solid fuel boiler if you include an additional unit in the heating system that can accumulate excess heat generated by the unit when burning a portion of fuel. Such nodes include buffer tanks or, which are also called drives.
Installing a heat accumulator allows you to:
- organize boiler maintenance at a convenient time of day;
- increase the time between successive fuel loads without reducing the comfort of living in the house;
- optimize home maintenance costs by reducing purchases solid fuel.
The use of solid fuel boilers together with buffer tanks allows you to reduce solid fuel costs significantly, while ensuring the required level of comfort in the house. The efficiency of installing a storage tank can be significantly increased if you use intelligent controllers and sensors in the heating system. When the set temperature values are reached in the premises of the house, the supply of coolant to the heating devices is stopped.
The heat generated by the boiler, which continues to operate, is accumulated in a buffer tank, and then transferred to the cooled coolant, which begins to circulate through the system, bypassing the burnt-out boiler. The larger the volume of the buffer tank, the longer the house will be heated due to the thermal energy accumulated in it.
Advantages of using a thermal storage tank in the heating system of a country house connected to several heat generators
How does a heat accumulator work?
The buffer tank is usually made in the shape of a cylinder from sheet steel(black or stainless). The volume of a heat storage tank can vary from hundreds to several thousand liters. The larger the volume of the container, the larger its dimensions. Due to the impressive linear dimensions of storage tanks, difficulties arise with their placement in boiler rooms. Manufacturers of ready-made heat accumulators produce models both with and without thermal insulation, supplied in separate packaging. The thickness of the insulation layer is usually 10 cm, which must be taken into account when installing equipment. A casing made of high-quality leather substitute is put on the tank with insulation. The insulation slows down the cooling of the coolant located in the heat storage tank.
Depending on the design, buffer tanks are:
- empty (without heat exchangers);
- with one or two coils (heat exchangers);
- with built-in boiler tanks of smaller diameter used to provide battery life hot water supply systems for a suburban facility.
The steel body of the tank is provided with several threaded holes, which are used to connect the storage device to the boiler and piping of the home heating system.
External view and internal structure of a thermal accumulator (buffer tank) with a lower heat exchanger and a layer of mineral wool insulation
How quickly are energy reserves used up?
It is impossible to give a definite answer to this question. Duration of work heating system object due to the energy accumulated in the buffer tank depends on:
- on tank volume;
- on the volume of heat loss in the room;
- on the outside temperature and time of year;
- from the set values of temperature sensors.
Heating a country house with the passive participation of boiler equipment can be carried out from several hours to several days. While the heat accumulator is working, the boiler “rests”, which means it retains its resource, which is enough for large quantity heating seasons.
How to choose the right model?
When choosing a model of a suitable buffer tank for heating a suburban property, one proceeds from the power of the heating boiler. Developed online calculators, allowing you to interactively determine the volume of the storage tank depending on the power of the solid fuel boiler and the time that the unit will need to heat the coolant in the buffer tank. You can also use ready-made tables containing recommendations on the volume of storage tanks for specific models of solid fuel boilers.
When choosing a thermal accumulator model, it is important to take into account its dimensions. Experts recommend installing buffer tanks in close proximity to the heating boiler. When using circulation pumps in the heating system, storage tanks can be located in the house, garage, or utility rooms.
How does the heat accumulator work when in the system?
A circulation pump embedded in the section of pipeline connecting the heating boiler to the buffer tank supplies heated water to the upper part of the heat accumulator. In this case, the cold coolant is pushed out from the lower part along the return line into the heating boiler.
Second circulation pump, installed between the buffer tank and the radiators, ensures the supply of hot coolant through the pipework until the thermostat turns it off due to the set air temperature being reached in the room.
When the heating devices cool down in the house, it will become colder, the sensors will work, and the pump will again begin to supply the heated coolant into the piping of the heating system. Thermal energy will be accumulated during periods of inactivity of the second circulation pump.
Connection diagram of a thermal accumulator to the heating system of a country house heated autonomously using a solid fuel boiler
If the heat accumulator is not used, then all the coolant goes into the system and the house overheats. Excess heat is removed from the rooms through open vents and windows. “Drowning the street,” throwing money away, is currently an unaffordable luxury and even criminal extravagance.
After all the fuel stored in the boiler furnace has burned out, the equipment is switched off. The first circulation pump stops operating, and the second continues to function, ensuring the supply of hot coolant stored in the container to the piping and radiator wiring of the heating system. The cooled coolant returns to the thermal accumulator, which each time lowers the temperature of the water in the thermos container.
You will learn about what fuel is best to use for heating a house and how to properly light a stove in our next article:.
What else can be connected besides the boiler?
In addition to boiler equipment, heat storage tanks can be connected to alternative sources heat (fireplace insert, etc.). The presence of such sources will make it possible in the summer not to heat the boiler at all, since the thermal energy they provide will be enough to heat hot water for the hot water system.
The disadvantages of using ready-made buffer containers include their high cost and large size. The costs are recouped depending on the volume of the heat accumulator over several years. If desired, you can make a storage tank yourself. This video shows an example of such a project.
Thermal accumulators are buffer tanks for storing excess heat generated during system operation autonomous heating. They are used in conjunction with different heat sources - solid fuel, gas or electric heating boilers. You can buy a heat accumulator at a profit Russian production in our company in Yekaterinburg, Belgorod, St. Petersburg, Kazan, Moscow. After this, you will be able to collect energy to further heat the air in the room, reducing the load on the boiler and ensuring its optimal operation.
Advantages of thermal accumulators
Options
It is possible to optimize heating by simultaneously connecting to solar panels and a pyrolysis boiler or any other combination of several energy sources.
Strength
The products are made from structural black and stainless steel up to 8 mm thick, therefore they are durable, reliable, not subject to burnout or deformation.
Versatility
Applicable for solving technical industrial and domestic needs with an electric meter of 2-3 tariff types. The range of sizes and capacities allows you to select the ideal equipment for a specific task within the allocated budget.
Energy efficiency
The heat exchanger built inside allows for better distribution thermal energy, increase boiler efficiency and save up to 30% of raw materials. If necessary, it is possible to install additional heat exchangers and auxiliary storage tanks modern type to reduce heating costs by up to 50 or even 75%.
Stability and protection
A heat accumulator for a heating boiler prevents its overload and overheating, due to the timely discharge of even a large amount of thermal energy and its rational use. This helps extend the service life of all elements of the heating system and ensures high level her safety.
Heat supply optimization
Promotes uniform distribution of heat in rooms, reducing the cost of organizing heating and hot water supply in buildings of any size and number of floors.
Battery tank connection diagram
Thermal accumulators are designed to accumulate, store and transfer excess thermal energy obtained from various sources. These sources can be solid fuel boilers, electric boilers, gas boilers, solar collectors and heat pumps.
Types and selection of heat accumulators
The BTS Boilers company sells a wide range of heat storage tanks to solve any technical problems. The catalog of offered products includes:
- EA series with built-in black steel heat exchanger.
- The EAI series is equipped with an upper heat exchanger made of moisture-acid-resistant AISI 304 stainless steel.
- The EAB series is equipped with a storage boiler made of AISI 304 steel.
- The EAM series is used in heating and air conditioning systems. It has wide possibilities for additional configuration to solve any design problems.
To quickly understand the range of heat accumulators offered, consider the following recommendations when choosing:
- The EAM storage tank is suitable for installation in a system operating from one boiler of any type.
- Thermal storage tanks series EAI and EA are a rational purchase for assembling a system powered from several energy sources.
- When organizing a hot water supply system with a large flow rate, heat accumulators of the EAI, VT and VVT series are used, which are capable of serving several water intake points with running water.
- To heat water as quickly and efficiently as possible and maintain the required values in the heating circuit, heat accumulators of the EAB series with a built-in boiler are used. It is reasonable to use equipment with a tank volume of 85, 160 and 250 liters.
Thermal accumulator compatibility
| Heat accumulators type EA | Thermal accumulators EAI | Thermal accumulator EAB | Thermal accumulator type EAM - 00 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| EA-00 | EA-10 | EA-01 | EA-11 | EAI-10 | EAI-11 | EAB-00 | EAB-10 | EAB-01 | EAB-11 | ||
| Solid fuel boiler | + | + | + | + | + | + | + | + | + | + | + |
| solar collector | — | — | + | + | — | + | — | + | + | + | + |
| A gas boiler | + | + | + | + | + | + | + | + | + | + | + |
| Electric boiler | + | + | + | + | + | + | + | + | + | + | + |
| Possibility of installing additional heat exchangers | — | — | — | — | — | — | — | — | — | — | + |
| Heating water for domestic needs | — | + | — | + | + | + | + | + | + | + | + |
| Possibility of installing an electric heater | + | + | + | + | + | + | + | + | + | + | + |
Since in many remote areas of the Russian Federation there is no gas supply, a wood-burning boiler for heating a private house with batteries is still a relevant solution to the heating issue. Modern models wood-burning equipment have an increased operating time from one load, are characterized by high efficiency and safety.
Operating principles of wood-burning boilers for private homes
Modern wood-burning boilers for heating a private house with a water circuit have little in common with traditional classic stoves. By design, most models resemble an autonomous thermal station. But the basic principle of operation remains unchanged. The heat obtained by burning solid fuels is used to heat rooms.A significant difference and change made in the internal structure is the presence of a water circuit. After modifying the design, it became possible to connect a radiator heating system in a country house with a wood-burning boiler.
On this moment, according to the principle of operation, two main classes of equipment can be distinguished: 
A solid fuel boiler is simply a modified wood stove, with better automation of the combustion process and high efficiency.
How to choose a wood-burning boiler for a private home
When choosing a heating boiler for a private home, several points regarding design features and performance are taken into account:- Heated area– approximate calculations of productivity are carried out using the formula 1 kW = 10 m². When connecting a second circuit for DHW, another 15-20% is added to the result obtained.
- Types of heating boilers– as already noted, there are classical units, as well as those that use the principle of pyrolysis combustion. The latter are considered the most economical wood-burning boilers individual heating private country estates. The first ones cost 3-4 times cheaper.
- Heat exchanger type- there are two types. It differs in the type of materials used and design. Boilers made of steel are cheaper, but last on average 10-15 years less. The units are not afraid of shocks and mechanical damage, and are easy to repair and maintain.
Cast iron boilers, on average, last about 35 years and have the best thermal characteristics. They are afraid of mechanical damage. Repair will require replacing the entire section. Another disadvantage of cast iron is the large weight of the boiler. A pyrolysis unit, which has two combustion chambers, easily reaches a mass of 5 centners. - Design features of the combustion chamber– Manufacturers produce boilers with side loading of firewood. The design is used in most units, both classical and pyrolysis types.
Top-loading boilers deserve special attention. This design is used in gas generating units. The main advantage of the solution is the possibility of pre-drying the firewood, which increases the heating efficiency. - Availability additional functions – automation, availability of a backup power source, built-in storage boiler, system remote control– all this increases the comfort of use and is available as an additional option.
Which boiler to choose?
If funds allow, it is better to install a wood-burning boiler of German or Czech production. Polish and domestic units are somewhat worse in terms of production characteristics. Among foreign and domestic manufacturing companies, the leaders are:- German wood boilers– represented by companies:
- Lopper.
- Czech-made wood-burning boilers– the company’s products deserve attention: In terms of quality and automation, the models are in no way inferior to their German counterparts, but cost on average 10% less.
- Russian-made boilers– TT units are produced by almost every heating equipment manufacturer. The boilers are adapted to domestic conditions and are unpretentious in terms of fuel quality and coolant used.
The most popular products are from the following factories:- Teplodar.
- Polish wood boilers– several dozen modifications are offered on the domestic market. Models in demand:
- DREWMET
- ORLAN.
Most manufacturers, in addition to classic heating boilers operating exclusively on wood, offer universal or multi-fuel heat generators.
Cost of wood boilers for country houses
The cost of the unit is influenced by several factors:- Type of heat exchanger - a cast iron boiler will cost 1.5-2 times more than a steel counterpart.
- Manufacturer.
- The principle of operation is that the cost of a wood-burning gas generator boiler from a domestic manufacturer will cost 35-40 thousand rubles, and the price of a boiler of a classical design will drop to approximately 20 thousand rubles.
- Additional equipment.
Heating installation in a private house with a wood-burning boiler
Wood-burning boilers with a water circuit for heating a private house are connected to an existing heating system with forced or natural circulation of coolant. During the installation work, comply with the requirements of PPB and SNiP.One more important issue One thing taken into account during connection is the need to accommodate a large fuel storage facility. The boiler burns 10-15 cubic meters of wood per season. The storage must be dry, accessible, spacious and safe.
Where can a wood boiler be installed?
A wood-fired hot water boiler for heating a private house can be installed anywhere, provided that it complies with the technical and fire safety requirements. General recommendations regarding the choice of premises for a boiler room are:
The main requirement for operating a wood-burning boiler is compliance with safety regulations. Modern models are equipped with a multi-level security system that prevents smoke in the room and boiling of the coolant.
Heating schemes for a private house with a wood-burning boiler
Heating installation in a private house using a wood boiler is being carried out different ways. The choice of wiring diagram largely depends on the design of the boiler and the parameters of the room. All options can be divided into several classes, according to the following features:
A liquid heating system connected to a wood-burning boiler requires proper planning and execution of work in strict compliance with all existing building codes. Particular care is taken to plan the heating distribution scheme in two-story house. Setting up a security group is required.
When installing, additionally connect voltage and uninterruptible power supply.
Modern wood-burning boilers are economical, safe and easy to control, and are successfully used as an alternative to gas equipment.